307 area code — Cheyenne, WY geographic
- State
- Wyoming
- Major area
- Cheyenne
- Time zone
- Mountain
- In service since
- 1947-01-01
- Active prefixes
- 495
- Rate centers
- 92
- Carriers
- 51
- Projected exhaust
- 4Q 2054
Area code 307 is a geographic code serving Cheyenne, Wyoming in the Mountain time zone. It has been in service since January 1, 1947. Because of number portability and VoIP, the area code tells you where the number was issued, not where the caller is right now.
NANPA lists 495 active NXX prefixes in 307, assigned to 51 carriers. 275 of those prefixes are pooled — shared between carriers in thousands-number blocks. The code spans 92 rate centers (billing localities).
Official projections put exhaust at 4Q 2054.
The dialing plan is 7D for home-NPA local calls and 7D across codes.
Among Wyoming codes, 307 stands out as the only area code serving Wyoming.
To check where a specific 307 number was issued, look up its six-digit prefix; to check who is actually calling, ignore the display and verify through an official callback number — caller ID is assertable and routinely spoofed.
Largest localities in 307
| Locality (rate center) | Active prefixes | Also served by |
|---|---|---|
| Cheyenne | 59 | — |
| Casper | 40 | — |
| Jackson | 21 | — |
| Gillette | 21 | — |
| Laramie | 18 | — |
| Rock Springs | 17 | — |
| Sheridan | 17 | — |
| Cody | 15 | — |
| Riverton | 13 | — |
| Evanston | 13 | — |
FAQ
Is 307 a toll-free number?
No. 307 is a geographic code; calls are billed like any other domestic call. Toll-free codes are 800, 833, 844, 855, 866, 877 and 888.
Will 307 run out of numbers?
NANPA's current forecast projects exhaust in 4Q 2054 — decades of capacity remain.
Why am I getting spam calls from 307 numbers?
Scammers spoof recognizable area codes so calls look local or familiar. A displayed 307 number does not prove the call originated there — see our guide to spotting spoofed calls.
Where is a 307 number from?
307 is assigned to Cheyenne and surrounding areas of Wyoming in the Mountain time zone. The three digits after the area code (the prefix) narrow it down to a rate center.